Case Presentation and EvolutionA seven-year-old male presented to the emergency department of a local hospital with sudden onset of mental status changes and jaundice. He had previously been a healthy child who was born and spent his first years of his life in India. He had normal growth and development. He was fully immunized and had also received the Bacillus Calmette-Guérin (BCG) vaccine. His past and family medical history was unremarkable, with the exception that his mother had been successfully treated for isoniazid (INH)-resistant tuberculosis (TB) three years previously. At that time, the patient had 14 mm of induration after a tuberculin skin test, and he and other members of the household were treated for 9 months with rifampin. His chest X-ray remained normal. He had not been previously hospitalized or had any previous surgery. The patient and his family moved to California's Central Valley several years before admission, and had not traveled since emigrating. The patient was an only child, and the family lived in a household with several healthy relatives and no pets. He was transferred to Stanford University Medical Center for potential liver transplantation.The patient first became ill two months before admission with the onset of abdominal pain and fever up to 40°C for six weeks. The cause of his fever was investigated on both an outpatient basis and during two inpatient admissions in the month that preceded transfer to Stanford University Medical Center. During the first admission, two possible diagnoses were pursued, including coccidiomycosis, because the patient resided in an endemic region, and TB, because of the patient's previous known exposure. A chest X-ray revealed hilar and peritracheal lymphadenopathy. An abdominal computed tomography (CT) scan was normal. A tuberculin skin test was negative, as was a gastric aspirate for acid-fast bacilli (AFB). Stool cultures for bacteria and parasites, and antibody tests for coccidiomycosis were negative. The patient was discharged on empiric treatment for both TB and coccidiomycosis, including ceftriaxone, fluconazole, ethambutol, INH, pyrazinamide, pyridoxine, and rifampin. On examination during his second admission, the patient was noted to have hepatosplenomegaly. An echocardiogram revealed a small pericardial effusion. Multiple serum acid-fast bacillus (AFB) smears were negative, and bronchoalveolar lavage was negative for fungus, bacteria, and AFB. However, he was started on empiric treatment for TB and coccidiomycosis with rifampin, INH, pyrazinamide, ethambutol, and fluconazole before being transferred to Stanford.When the patient arrived in the intensive-care unit, he was febrile with normal vital signs. Physical examination revealed a cachectic, combative young male who was not oriented and not able to follow commands. His conjunctivae were icteric. His neurologic examination revealed